Hello,
I have experience with the implementation of OpenVPN on a large scale and i think this experience could benefit you. I have implemented OpenVPN as a backbone communication solution for a large bike sharing system in Europe (50 stations and 1000 bikes). This is my first bid on a project and i must confess i haven't seen many details about your request, so i have a few questions on my own:
How many users will this solution serve?
Are you aiming for a High Availability solution or just a stand alone server
What is your deadline and what type of documentation would you like to receive along with the installation (User Manual, Troubleshooting Guide, FAQs?.. )
Regards,